Multi-stream gas chromatographic method and apparatus

ABSTRACT

Apparatus and method for rapid chromatographic analysis of gaseous mixtures. Apparatus includes a programming valve arrangement comprising an eight port valve block, having a single channel and having a movable valve plate member slidably affixed thereto by a valve plate carrier which in a first position permits simultaneous sampling of the gas stream to be analyzed and back flushing of the chromatograph column and in a second position rapid analysis of the gas sample. By the addition of one or more six port programming valves or equivalent sampling means in series with the eight port valve, the apparatus may function to rapidly analyze two or more separate gas streams.

United States Paten [1 1 Jones Y Y 1 Apr. 2,v 1974 .[22] Filed:

[ 1 MULTLSTREAM GAS Cl-lROMATOGRAPHlC METHOD AND APPARATUS [75] Inventor: A. William Jones, Wilson, NY.

[73] Assignee: Hooker Chemical Corporation,

Niagara Falls, NY.

Oct. 26, 1972 [21] App]. No.: 301,032

[52] US. Cl. 73/23.1, 73/422 GC [51] Int. Cl. G0ln 31/08 [58] Field of Search 73/422 GC, 23.1

[56] References Cited UNITED-STATES PATENTS 3,112,639 12/1963 Maxwell 73/23.1 3,267,736 8/1966 Boettger 73/422 GC 2,846,121 8/1958 Ronnebeck 73/422 GC 3,447,360 6/1969 Laseter 73/23.1 3,489,011 H1970 Firman 73/422 3,501,961 3/1970 Hable et al. 73/422 Primary Examiner-S. Clement Swisher Attorney, Agent, orFirm-Peter F. Casella; Richard P.

Mueller; Monroe D. Edelman [57] ABSTRACT Apparatus and method for rapid chromatographic analysis of gaseous mixtures. Apparatus includes a programming valve arrangement comprising an eight port valve block, having a single channel and having a movable valve plate member slidably affixed thereto by a valve plate carrier which in a first position permits simultaneous sampling of the gas stream to be analyzed and back flushing of the chromatograph column and in a second position rapid analysis of the gas sample. By the addition of one or more six port programming valves or equivalent sampling me'ansin series with the eight port valve, the apparatus may function to rapidly analyze two or more separate gas streams.

10 Claims, 9 Drawing Figures PATENTEDAPR 2mm 3 800 602 sum 5 [IF 5 BACKGROUND OF THE INVENTION This invention relates to gas chromatography. More particularly it relates to an arrangement of components comprising an improved programming valve, a single chromatographic column and a dector means arrangement for rapid analysis of gaseous mixtures. 7

Gas chromatography is an analytical technique widely used for the qualitative and quantitative analysis of gaseous mixtures. In recent years this technique has become increasingly important in determining components present in a sample to be analyzed. In general, a sample of a gaseous mixture is obtained from a gas stream and passed through one or more columns wherein the components are separated and then separately passed to a detector which measures the separated components of the mixture in order of their elution times. Columns may be then backflushed to remove any retained components from the column.

It is known to provide means such as a sampling valve wherein a small sample of a gaseous mixture is measured and then carried into the column by means of a carrier gas, in which column the components of the gaseous mixture are separated and gradually eluted from the column into the detector means. In the chromatographic analysis of a sample containing both easily and difficultly eluted components, the more rapidly eluted component is-separated and passed into the detector well before the more difficulty eluted component leaves the chromatographic column. When this type of analysis is being run, it is common practice to backflush the chromatographic column with a stream of carrier gas or a suitable flushing gas to remove the retained components at the inlet end of the chromatographic column. Backflushing of this type frees the column for another'a'nalysis. Suitable valving and lines must be supplied in addition to the basic apparatus to permit this backflushing.

In many chromatographic analyses two or more chromatographic columns are connected in series. It is also known to provide one or more valves programming the several carrier and backflushing gas streams as well as sample gas streams to efficiently operate the chromatographic analysis. Such arrangements as are presently known, involving several columns and/or several valves, are time'comsuming and add to the equipment and maintenance costs.

In one suchchromatographic analysis for hydrogen in a chlorine gas stream, three programming valves and two columns are used, together with a thermal conductivity detector. The analysis requires a three minute operation cycle during which a sample normally containing chlorine, water, carbon dioxide, carbon monoxide, oxygen, nitrogen and hydrogen passes into the sample loop and back into the plant stream via a sample cut-out valve. When an analysis is made, a programming valve causes a fixed volume of the sample to be trapped in a sample loop which is then purged by the carrier gas and the mixture is passed through the column. Separated hydrogen reaches the detector where its concentration is measured. Oxygen, nitrogen, carbon monoxide reach the detector later as a group and are intentionally not recorded. Carbon dioxide, chlorine. and water remain in the columns temporarily and are expelled by backflushing, using the third programming valve, whereby the original carrier gas is returned counter-currently through the columns and vented. A third carrier gas stream flows to the detector to keep it in equilibrium. In this way, the analyzer section is cleaned out and readied for the next analysis. As can be seen this technique, which is typical of the known chromatographic analyzing systems, involves two columns, three programming valves, and requires a carrier gas stream, a separate backflushing gas stream, and a third carrier gas stream flowing to the detector.

OBJECTS OF THE INVENTION It is therefore a primary object of the present invention to provide an improved gas chromatographic method or separating and measuring components from a gas stream.

Another object of the present invention is to provide such a method which requires one column and an improved programming valve.

It is also an object of the present invention to provide a gas chromatographic apparatus comprising an eight port programming valve providing simultaneous sampling and backflushing arrangements. I

Another object is to provide a method and apparatus for chromatographic analysis which requires a signle column and detector means for analysis of several streams.

These and other objects and advantages of the present invention will become apparent from the following specification.

BRIEF DESCRIPTION OF THE INVENTION The apparatus for the present invention comprises an eight port programming valve arrangement for use with a chromatographic column and a detector means communicating with a column at one end and at the other end with the programming valve. The programming valve includes a valve block having eight ports or apertures therein for enabling respective communication with one carrier medium and a gaseous sample medium, a movable valve plate member mounted on'one face of the valve block slidably affixed thereto by a valve plate carrier. The valve plate is provided with a plurality of apertures or channels for selective communication with predetermined ports of the valve block. The valve block is provided also with one channel which communicates selectively with predetermined channels of the valve plate. The valve plate is movable by the valve plate carrier to one or another of two positions on the valve block. The valve plate carrier may be operated manually or by automatic means.

In a first position, the gas sample flows into the valve block, over communicating channels in the valve plate, back into the block, filling a sample loop therein continuously with fresh sample. Simultaneously, the carrier gas flows into the valve block, over a communicating channel in the valve plate, out of the block into the detector and back through the column, flushing out the column, thence back into the block, over a communicating channel of the valve plate, and out of the block to the vent.

In the second position the carrier gas flows into the block over a communicating channel of the valve plate, back into the valve block, through the sample loop, picking up the measured amount of the sample from the sample loop, over a communicating channel of the valve plate back into and out of the block into the column, wherein the components of the gaseous sample are separated. The carrier gas elutes the lighter components of the gas sample from the column through the detector wherein the eluted gas components of interest are measured, and then flows from the detector back into the valve block, over the communicating channel of the valve plate, back into the block, and out of the block to the vent. During this time, communicating channels of the valve plate and block permit uninterrupted flow of the gaseous sample stream through the valve by-passing the sample loop.

The valving technique herein described enables one eight port valve to permit sampling and analysis ofa gas mixture and also backflushing of the column. It also permits carrying a stream directly to the detector from the column without intervening passages or conduits. In addition to simplicity, rapidity is gained. In most instances, the analysis is accomplished in a matter of seconds rather than minutes as in previous chromatographic analyses. This procedure and apparatus eliminates most causes of peak broadening, since the eluted material flows directly-from the column to the detector rather than through intervening apparatus units.

A particular advantage of this invention is that the apparatus unit isportable and can be connected to an electrolytic chlorine-caustic cell or header and an analysis of the evolved gas mixture completed in less than one minute, usually less than 30 seconds.

DETAILED DESCRIPTION OF THE INVENTION A better understanding of the method and apparatus of the present invention may be had from the following description of the construction and operation of several embodiments thereof and illustrated by the accompanying drawings in which:

FIG. 1 is an exploded view of combined sampling and backflushing valve portion of the apparatus of the present invention.

FIG. 2 is a view of the port surface of the eight port valve block having thereon one channel.

FIG. 3 is a sectional view of the valve plate showing the arrangement of its five channels for selective communication with the ports and channel of the eight port valve block.

FIG. '4 is a schematic view of an embodiment of the apparatus of the present invention in its backflushing and sample loading position.

FIG. 5 is a schematic view of the same embodiment of the apparatus of the present invention in its sample injection and analyzing position.

FIG. 6 is a view of the port surface of a six port sampling valve block.

FIG. 7 is a sectional view ofa valve plate having four channels for selective communication with the ports of a six port valve block.

FIG. 8 is a schematic view of an embodiment of the invention wherein two six port sampling valves and one eight port backflushing and sampling valve are combined..The valve plates are in a first position wherein the valves are set up to permit backflushing of the column and filling of the sample loops of each of the three valves with a gas sample to be analyzed.

FIG. 9 is a schematic view of the same three valve arrangement in a second position wherein a sample of a gaseous mixture in the sample loop of the eight port valve is carried through the apparatus shown into the chromatographic column and detector means. In these schematic views the interface between the valve plate and the valve block is depicted so that passages in both the plate and the block may be seen.

With reference to FIG. 1, it will be seen that the valve comprises a valve block 18 having eight ports 1 to 8 running through the solid block and each port being connected by means of tubing to various supply means and analyzing units not shown and a channel 9 in the surface of the block, a valve plate 19 having therein five channels 10 to 14, said valve plate being slidable upon the valve block in two positions so as to provide predetermined communication among the ports of said block and the channels of said plate (as hereinafter disclosed), said plate being held in slidable contact with said block by valve plate carrier 20 and tensioning means not shown so the passages form a gas tight system.

FIG. 2 shows the arrangement of the ports 1 to 8 and the channel 9 in the valve plate block 18 of the 8 port sampling and backflushing valve.

FIG. 3 shows the arrangement of the channels 10 to 14 in the valve plate 19 of the sampling and backflushing valve.

FIG. 4 and FIG. 5 illustrate the operation of a preferred form of the apparatus of this invention. The valve (see FIG. 1) which comprises the valve block 18 having the valve plate 19 held slidably affixed thereto by valve plate carrier 20 is connected to a suitable chromatographic column 16 and a detector means 17 which is connected to the valve thereby forming a closed system.

In FIG. 4, the valve plate 19 is positioned so as to connect ports 1 and 2 by channel 11, ports 3 and 4 by channel 12 ports 5 and 6 by channel 13 and ports 7 and 8 by channel 14. Thus, a gas stream to be analyzed, entering the valve at port 5, flows through the valve block 18 to the valve plate 19 through channel 13 back to the valve block 18 at port 6 thence through the sample loop 15 and through port 3 to valve plate 19 through channel 12 back to the valve block 18 exiting to the sample vent through port 4. Simultaneously, a stream of carrier gas enters the valve block 18 to port 2, flows through channel 11 of the valve plate 19 to port 1, and from which the carrier gas is directed through detector 17 to column 16, passes through the column in the op posite direction to the direction of flow during an analysis, returns to port 7 of valve block 18, thence flows through channel 14 of valve plate 19 to port 8 of the valve block 18 and exits to the vent. In this manner, a sample of the gas stream to be analyzed has been introduced in the sample loop 15 formed by the piping means connecting ports 6 and 3 of the valve block 18 while the column has been cleared of residues from a preceding sample analysis by the carrier gas stream in a backflushing manner.

Thereafter, as illustrated in FIG. 5, the valve plate 19 is shifted by the valve plate carrier 20 to its alternate position, so as to connect ports 2 and 3 by channel 1 1, ports 4 and 5 by channels 12, 9 and 13, ports 6 and 7 by channel 14 and ports 8 and l by channel 10. Thus, the gas stream entering the valve block 18 at port 5 passes through channel 13 of the valve plate 19, across channel 9 of the valve block 18, through channel 12 of the valve plate 19 into port 4 of the valve block 18 and exits to the gas stream line or vent. Carrier gas, entering the valve block 18 to port 2 passes through channel 1 l of the valve plate 19 to port 3 of the valve block 18 through the sample loop 15 picking up the gas sample to be analyzed, returning to valve block 18 through port 6 thence passes through channel 14 of the valve plate 19 to port 7 of the valve block 18, from whence the carrier gas containing the gas sample to be analyzed is directed into and through the column 16. The gas stream exiting from the column 16 passes through detector l7 and from there back into the valve block 18 at port 1 through channel of the valve plate 19 to port 8 of the valve block 18 from which the gas stream is exited to the vent.

As can be seen the valve block and valve plate assembly shown in FIG. 4 is in the combined backflushing and gas sampling position while that illustrated in FIG. 5 is in the sample injection and gas analyzing position.

In operation, the multi-valve arrangement shown in FIGS. 8 and 9 permits the rapid analysis of three separate gas streams. Inclusion of additional six port sampling valves in series arrangement permits the expansion of this system to additional gas stream(s) analyses. Likewise removal of one of the six port valves from the indicated arrangement decreases the system to the analysis of but two gas streams.

With reference to FIG. 8 the valve arrangement is such as to ermit the simultaneous backflushing of the column 16 with the carrier gas and filling of the sample loops 15, 49 and 50 This apparatus comprises one eight port backflushing and sampling valve 18, two six port sampling valves comprising valve blocks 45 and 46 respectively, a column 16, and a detector means 17. The two six port valves are identical in construction each comprising a valve block having six ports (identified by numerals 21 through 26 for valve block 45, and by numerals 31 through 36 for valve block 46), a valve plate 47 having four channels (identified by numerals 27 through 30 for valve block 45, and a valve plate 48 with four channels 37 through 40 for valve block 46). Each has a valve plate carrier (not shown) and tensioning means (not shown) which serve to maintain the valve plate in slidable contact with the valve block and seal the gas passages. The valve plate is thus movable eithermanually or automatically over the face of the valve block between two positions permitting predetermined communication of the channels of the valve plate with the ports of the valve block.

In operation of this multi-valve arrangement, in the backtlushing position, the carrier gas enters the valve block 18 at port 2, flows over channel 11 of the valve plate 19 to port 1, and is directed through detector means 17 to column 16, flowing in a direction opposite to the normal flow through the column and flushes retained material from the column back to the valve arrangement entering at port 34 of the valve block 46, passing across channel 39 of the valve plate 48 to port 33 of valve block 46 to port 24 of valvevblock 45 across channel 29 of the valve plate 47 to port 23 of valve block 45 to port 7 of the valve block 18 across channel 14 of the valve plate 19 to port 8, from which the carrier gas stream containing the material flushed from column 16 is discharged to the vent.

Simultaneously, samples of three separate gas streams are being obtained for analysis. Thus, a first gas stream enters the eight port valve at port 5 of valve block 18, passes across channel 13 of valve plate 19 to port 6 into the sample loop connecting ports 6 and 3, and thence across channel 12 of valve plate 19 to port 4 from which the gas stream is directed to vent pine 43. A second gas stream enters valve block 45 at port 26, passing across channel 30 of the valve plate 47 to port 25 and into the sample loop 49 connecting ports 25 and 22, and thence across channel 28 of the valve plate to port 21 from which the gas stream is directed from valve block 45 to vent pipe 43. A third gas stream is introduced into port 36 of the valve block 46 and passes across channel 40 of the valve plate 48 to port 35 and into the sample loop 50 connecting port 35 and port 32, thence the gas stream passes across channel 38 of the valve plate to port 31 from which it is directed to vent pipe 43.

To carry out the analysis of the first gas stream, the valve plate 19 is moved by valve plate carrier 20 to the alignment on valve block 18 illustrated inFIG. 9. As illustrated therein, carrier gas enters the eight port valve at port 2 of valve block 18 andpasses across channel 11 of valve plate 19 to port 3 into sample loop 15, picking up the measured sample therein, to port 6 across channel 14 of valve plate to port 7 from which the carrier gas containing the gas sample to be analyzed flows through valve block 45 entering it at port 23 and passes across channel 29 of the associated valve plate 1 47 to port 24 and thence to valve block 46 entering it at port 33 passing across channel 39 of the associated valve plate 48 to port 34 from which the carrier gas and the sample are directed to and through the column 16. In the column the components of the gas sample are separated and eluted, the eluted fractions passing to the detector 17 for measurement. Thereafter the gas stream is directed back to the eight port valve entering it at port 1 of valve block 18 and passes across channel 10 of valve plate 19 to port 8 from which it is vented from the system. During the period of analysis of the gas sample from the eight port valve which requires a period of from about 30 seconds to several minutes, depending upon the ease of separation of the components of the sample, the second and third gas streams continue to flow as indicated in FIG. 9, while the gas stream entering the eight port valve at port 5 of valve block 18 passes through channels 13, 9 and 12 to port 4 and is directed from the valve to vent pipe 43.

Following completion of the analysis of the gas sample of the eight port valve, the valve plate 47 associated with six port valve block 45 is moved to its alternate position by means of the valve plate carrier associated therewith. Thereafter, carrier gas flowing from port 7 of the valve block 18 enters valve block 45 at port 23, passes through channel 28 of the'valve plate to port 22 and flushes the gas sample contained in sample loop 49 through port 25 and channel 30 to port 24 to valve block 46, entering it at port 33, across channel 39 of the valve plate 48 associated with the valve block 46 to port 34 from whence the carrier gas containing the gas sample to be analyzed is directed to the column 16 and from the column to detector 17 for analysis and measurement, back to the eight port valve, entering it at port 1 of the valve block 18, theanalyzed gas stream passing across channel 10 of valve plate 19 to port 8 of the valve block 18 from which the gas stream is vented from the system. During this stage of the analysis, the gas stream entering valve block 45 at port 26 passes across channel 27 of the valve plate 47 to port 21 from which it is discharged into vent pipe 43 so its flow is uninterrupted.

In analogous manner, by moving the valve plate 48 of valve block 46 to its alternate position, the carrier gas stream from port 24 of valve 45 enters port 33 of valve block 46, picks up the gas sample contained in sample loop 50, leaving valve block 46 at port 34 and flows through column 16 and detector 17 for analysis and measurement, back to the eight port valve, at port 1 of valve block 18. The gas stream flowing to valve 46 enters it at port 36 and exits from port 31 to vent pipe 43 so its flow is uninterrupted.

Following completion of the third sample analysis, the valve plates of each of the valves are moved to the original positions as illustrated in FIG. 8 and the column is again backflushed and simultaneously the sample loops of each of the valves are filled with measured samples of the three gas streams.

By this procedure and apparatus, three streams may be analyzed efficiently and rapidly. When the gas streams are chlorine gas streams from electrolysis of brine, the streams can be analyzed for hydrogen using nitrogen as the carrier gas. Each analysis requires about 30 seconds, and on a continuous basis, three such chlorine gas streams can be monitored for hydrogen content in about a 2 to about 6-minute cycle.

The valve block is constructed preferably of an acid resistant metal, such as stainless steel, l-lastelloy, tantalum or the like. For special applications, acid resistant plastic materials such as perfluorohydrocarbons TEF- LON and halogenated polyesters HETRON may be used. The valve plate is generally constructed of an acid resistant self-lubricating sealing plastic material,

such as TEFLON, although acid resistant metals can be used also.

Detector means and chromatographic column used with this apparatus are conventional units and are well known in this art. Detector means is preferably of thermal conductivity type and preferably uses tungsten alloy filaments.

Carrier gas system used in this method may be helium, nitrogen, methane or any other carrier gas used in gas chromatographic analysis. Helium is the gas usually used in connection with thermal conductivity detectors because of its safety and response. ln the embodiments of this invention, specifically related to analysis for hydrogen in chlorine, nitrogen is used because its response and linearity are much greater than those of helium. This permits operating with lower detector current and greatly increases detector life. This, and nitrogens availability, economy, and safety make it preferred for this particular analysis.

The carrier gas is passed through a nonbleed type pressure regulator on top of the analyzer. At the flow control manifold the carrier supply is split, one stream passing through a flow restrictor to the backflushing and sampling valve and the column side of the detector means, the remaining stream passing through a separate flow restrictor to the reference side of the detector means. The flow rate through the column and the detector means is in the 30 to 45 cc per minute range. Too great a flow can result in reduced peak height while too low a flow slows down the analysis. The restrictor upstream of the reference port of the detector means is set, in most cases at about cc per minute. In this range the flow rate adequately purges the reference cell of the detector without wasting the carrier supply.

Only one column is required for use in the method of this invention. Any suitable column for separating hydrogen in chlorine gas, in the preferred modification, can be used. A typical column suitable for this procedure is a one-fourth inch OD nickel tubing, 4 ft. in length packed with 50/60 mesh silica gel. Such a column can, as is known, can be activated by heating to 300 C for 2 hours while passing a flow of carrier gas through it. The activated silica gel permits hydrogen to elute very quickly, but holdsair back sufficiently long to keep it from interfering with the hydrogen peaks. Carbon dioxide is held back longer than three hydrogen peaks and chlorine even more. Such a column permits putting samples from at least three streams on the column measuring hydrogen in each as it elutes and then reversing the flow before carbon dioxide and chlorine from even the first sample reaches the detector means.

It is also possible by suitable valving arrangements of the feed gas stream to utilize one chromatograph of this design with no more complexity than the conventional two column unit to monitor hydrogen in three separate chlorine gas streams.

While this apparatus and method have been described for the detection of hydrogen in chlorine gas streams, it is suitable for use in analysis of other gaseous mixtures with equal accuracy and facility. As examples of such of the gaseous mixtures, the following are mentioned as typical:

a. hydrogen chloride and water vapor mixtures,

b. chlorinated organics, such as mixtures of 0-, m-,

and p-chlorotoluenes,

c. hydrocarbon mixtures such as mixtures of methane, ethane, propane and acetylene.

As will be evident to those skilled in this art, the operation of the chromatographic analysis system of this invention can be operated either manually or by automatic means. ln the latter instance a conventional electronic programmer can be utilized to establish a time cycle for control of the gas flows through the programming valve(s), column, and detector means and to transfer the detector signal to a recording means.

What is claimed is:

1. Apparatus for rapid chromatographic analysis of gaseous mixtures comprising 1. a programming valve 2. a chromatographic column having an inlet and outlet, and

3. a detector means having an inlet and an outlet, said programming valve communicating with the inlet of the chromatographic column and with the outlet of the detector means, the outlet of the column communicating with the inlet of the detector means, said programming valve including a valve block member having eight ports and one channel, two of said ports forming the inlet and outlet for a sample loop means included within said valve block, a movable valve plate member positioned on one face of said valve block and having thereon a plurality of channels, said valve plate being movable by a valve plate carrier between two positions on the valve block permitting selective communication of predetermined ports, and channel of the valve block and predetermined channels of the valve plate and with the inlet of the column and the outlet of the detector means.

2. Apparatus as claimed in claim 1 wherein one port in the valve block communicates with a carrier gas supply stream and another port communicates with a source of the gaseous mixture to be analyzed, the programming valve being such that when the valve plate is in a first position with respect to the valve block ports and channel the carrier gas stream flows in a back flushing manner through the programming valve to the detector means and column and simultaneously the gaseous mixture entering the programming valve flows into and fills the sample loop, and when the valve is in a second position, the carrier gas stream port communicates with the sample loop ports so that the carrier gas flowing into the programming valve displaces the sample of gaseous mixture from the sample loop, the flow of carrier gas and sample of gaseous mixture being directed to the inlet of the chromatographic column.

3. Apparatus as claimed in claim 2 wherein the valve plate is movable by manual means.

4. Apparatus as claimed in claim 2 wherein the valve plate is movable by automatic means.

5. Apparatus as claimed in claim 2 wherein the channel of the valve block communicates with the port through which the gaseous mixture is admitted to the valve block when the valve plate is in a second position thereby permitting the gaseous mixture to flow through the programming valve in a steady stream bypassing the sample loop.

6. Apparatus as claimed in claim 2 wherein at least one additional programming valve is inserted in series arrangement between the programming valve of said apparatus and the inlet of said column said additional programming valve comprising a valve block member having six ports, two of which forming the inlet and outlet for a sample loop means included within said valve block, said inlet port of each valve block communicating with a different source of gaseous mixture to be analyzed, a movable valve plate member positioned on one face of said valve block and having a plurality of channels thereon, said valve plate being movable by a valve plate carrier between two positions on the valve block permitting selective communication of predetermined ports of the valve block and predetermined channels of the valve plate and with the inlet of the column and predetermined ports of the adjacent programming valves.

7. Apparatus as claimed in claim 6 wherein three programming valves are connected in series arrangement, a first programming valve, comprising an eight port valve block communicating with the outlet of the detector means and a second programming valve comprising a six port valve block, which second valve communicates serially with a third programming valve, the latter communicating serially with the inlet of the chromatographic column.

8. A method for rapid chromatographic analysis of gaseous mixtures which comprises passing a stream of a gaseous mixture to be analyzed through a sample loop section of a multiport programming valve thereby to fill said sample loop with a measured sample of said gaseous mixture while simultaneously passing a stream of carrier gas through said programming valve to and through a detector means, into and through a chromatographic column and thereafter back into and through said programming valve, said flow of carrier gas continuing until substantially all the components of the gaseous mixture retained in said column from a previous analysis have been removed from said column, then altering the flow of the carrier gas stream through the programming valve to cause it to pass into and through the sample loop and to displace the gaseous sample from said loop, passing the carrier gas and gaseous mixture from the programming valve into the column wherein a separation of the components of the gaseous mixture occurs, while simultaneously directing the flow of gaseous mixture through the programming valve bypassing the sample loop.

9. The method of claim 8 wherein the gaseous mixture to be analyzed is a mixture comprising chlorine and hydrogen.

10. The method of claim 9 wherein the gaseous mixture is a chlorine gas stream produced by the electrolysis of brine. 

1. Apparatus for rapid chromatographic analysis of gaseous mixtures comprising
 1. a programming valve
 2. a chromatographic column having an inlet and outlet, and
 3. a detector means having an inlet and an outlet, said programming valve communicating with the inlet of the chromatographic column and with the outlet of the detector means, the outlet of the column communicating with the inlet of the detector means, said programming valve including a valve block member having eight ports and one channel, two of said ports forming the inlet and outlet for a sample loop means included within said valve block, a movable valve plate member positioned on one face of said valve block and having thereon a plurality of channels, said valve plate being movable by a valve plate carrier between two positions on the valve block perMitting selective communication of predetermined ports, and channel of the valve block and predetermined channels of the valve plate and with the inlet of the column and the outlet of the detector means.
 2. a chromatographic column having an inlet and outlet, and
 2. Apparatus as claimed in claim 1 wherein one port in the valve block communicates with a carrier gas supply stream and another port communicates with a source of the gaseous mixture to be analyzed, the programming valve being such that when the valve plate is in a first position with respect to the valve block ports and channel the carrier gas stream flows in a back flushing manner through the programming valve to the detector means and column and simultaneously the gaseous mixture entering the programming valve flows into and fills the sample loop, and when the valve is in a second position, the carrier gas stream port communicates with the sample loop ports so that the carrier gas flowing into the programming valve displaces the sample of gaseous mixture from the sample loop, the flow of carrier gas and sample of gaseous mixture being directed to the inlet of the chromatographic column.
 3. Apparatus as claimed in claim 2 wherein the valve plate is movable by manual means.
 3. a detector means having an inlet and an outlet, said programming valve communicating with the inlet of the chromatographic column and with the outlet of the detector means, the outlet of the column communicating with the inlet of the detector means, said programming valve including a valve block member having eight ports and one channel, two of said ports forming the inlet and outlet for a sample loop means included within said valve block, a movable valve plate member positioned on one face of said valve block and having thereon a plurality of channels, said valve plate being movable by a valve plate carrier between two positions on the valve block perMitting selective communication of predetermined ports, and channel of the valve block and predetermined channels of the valve plate and with the inlet of the column and the outlet of the detector means.
 4. Apparatus as claimed in claim 2 wherein the valve plate is movable by automatic means.
 5. Apparatus as claimed in claim 2 wherein the channel of the valve block communicates with the port through which the gaseous mixture is admitted to the valve block when the valve plate is in a second position thereby permitting the gaseous mixture to flow through the programming valve in a steady stream bypassing the sample loop.
 6. Apparatus as claimed in claim 2 wherein at least one additional programming valve is inserted in series arrangement between the programming valve of said apparatus and the inlet of said column said additional programming valve comprising a valve block member having six ports, two of which forming the inlet and outlet for a sample loop means included within said valve block, said inlet port of each valve block communicating with a different source of gaseous mixture to be analyzed , a movable valve plate member positioned on one face of said valve block and having a plurality of channels thereon, said valve plate being movable by a valve plate carrier between two positions on the valve block permitting selective communication of predetermined ports of the valve block and predetermined channels of the valve plate and with the inlet of the column and predetermined ports of the adjacent programming valves.
 7. Apparatus as claimed in claim 6 wherein three programming valves are connected in series arrangement, a first programming valve, comprising an eight port valve block communicating with the outlet of the detector means and a second programming valve comprising a six port valve block, which second valve communicates serially with a third programming valve, the latter communicating serially with the inlet of the chromatographic column.
 8. A method for rapid chromatographic analysis of gaseous mixtures which comprises passing a stream of a gaseous mixture to be analyzed through a sample loop section of a multiport programming valve thereby to fill said sample loop with a measured sample of said gaseous mixture while simultaneously passing a stream of carrier gas through said programming valve to and through a detector means, into and through a chromatographic column and thereafter back into and through said programming valve, said flow of carrier gas continuing until substantially all the components of the gaseous mixture retained in said column from a previous analysis have been removed from said column, then altering the flow of the carrier gas stream through the programming valve to cause it to pass into and through the sample loop and to displace the gaseous sample from said loop, passing the carrier gas and gaseous mixture from the programming valve into the column wherein a separation of the components of the gaseous mixture occurs, while simultaneously directiNg the flow of gaseous mixture through the programming valve bypassing the sample loop.
 9. The method of claim 8 wherein the gaseous mixture to be analyzed is a mixture comprising chlorine and hydrogen.
 10. The method of claim 9 wherein the gaseous mixture is a chlorine gas stream produced by the electrolysis of brine. 